Self-organisation phenomena during electrodeposition of palladium–indium alloys

Abstract

The present investigation was focussed on determining the appropriate electrolyte for the deposition of palladium–indium alloy in a wide range of indium content and to investigate the possibility of observing spatio-temporal structures on the electrode surface. From polarisation experiments, it was established that the palladium–indium phase deposits at more positive potentials than the pure metals and this results at low current densities (0.1–0.3 A dm−2) in the content of the coatings being about 9–17 wt-% In. In the coatings obtained the formation of spatio-temporal structures during electrodeposition of palladium–indium alloys was observed for the first time. The period of the structures is 50–200 µm. The optically different areas of the structures show similar elemental and phase content as well as similar morphology. X-ray analysis of the sample with spatio-temporal structures shows superposition and coincidence of the spectra of the phases Pd and Pd0.85In0.15. This result is in agreement with those obtained during investigation of other electrodeposited alloys (Аg–In, Ag–Sb, Ag–Cd, In–Co, etc.) with spatio-temporal structures, which appear when simultaneously deposition of two phases with identical crystal lattice takes place.